The invention relates to a container for handling knife blades, in particular such as is used for the storage, transport and individual removal of blades.
Such containers are used in particular where the need arises to make blades available for cutting operations. Manual cutting or filleting processes are often performed using a knife, the knife comprising a re-usable handle and a throw-away blade taken from the container. The blades are conventionally arranged in stacks which lie flat and are secured in a box, generally made out of cardboard. As long as the package is completely filled the blades in it cannot move and cause their cutting edges to strike against one another. With increasing removal of blades individual blades can however move back and forth in the pack and in particular the vulnerable cutting edges of the blades can strike against other blades. As the cutting edge is finished to a fine degree in the micron region, it is a delicate, very sharp but statically extremely vulnerable micro system which, when it comes into contact with hard objects can be damaged or even destroyed by only slight forces. Any damage, which may not be visible to the naked eye, makes the blade a scrap component, since the cutting function of the blade is achieved by the cutting edge alone.
Since the cutting operations described above are mostly performed as piece work such damaged knife blades have an adverse effect on the piece work performance of the worker, who therefore often takes out a further new blade, resulting in increased costs for the manufacturing operation.
Furthermore, such knife blades may be used to provide cutting machines with one or more blades operating simultaneously. In blades thus stored in xe2x80x9cloose orderxe2x80x9d this results in costs which are avoidable from several aspects. In the setting up of a cutting machine with for example 40 simultaneously operating knife blades, the operator finds it advisable to lay out the blades in a way which makes them easy to pick up. Picking up blades which lie spread around in a box, by contrast, takes up time and gives rise to a danger of injury. Another disadvantage is that when even only one blade in the set has a blunt cutting edge as a result of faulty storage, the whole set may be rejected. Overall an indeterminate and unpredictable risk of rejection results from the conventional way of storing knife blades.
In current practice, when the blades are put in the box it is filled up with filling materials in order to locate the blades, at least initially. Also when a conventional box for blades is only to be half-filled with blades (half pack size) the empty space left in the box is normally filled up in a material-intensive way using foam or cardboard filling.
Accordingly it is an aim of the present invention to provide an improved container for knife blades as well as to improve the removal of the blades.
According to the present invention, a container for knife blades has an internal cavity, said internal cavity holding knife blades arranged side by side in a stack, and a slide member located in said container and in engagement with said stack of knife blades, said slide member being adapted to move to reduce the size of said internal cavity.
Thus the container according to the invention has an internal cavity for holding the stack of knife blades, and which can be reduced in size according to the size of the stack by means of the slide member, whereby the result is achieved that the blades mounted in the container do not move around and cannot strike against one another. In particular this achieves the result that after the manufacture of the blade the finely finished cutting edge can only come into contact with the packaging, generally of cardboard or plastics, so that the cutting edge is not damaged.
In one embodiment the slide member can slide in only one direction, e.g. by means of a guide based on the ratchet principle, the slide being capable of being urged in a direction towards the stack of blades with minimal force, but not being able to slide back. Accordingly the location is still maintained even in the event of a shock or impact against the container, e.g. on it falling over or being dropped.
If the slide member and the rail are provided with mutually inter-engaging detents, a stepwise adjustment of the position of the slide is made possible, an increased force needing to be applied to overcome a detent position.
According to one particularly preferred embodiment the interengaging detents are of sawtooth form. When it is desired to move the slide towards the stack of blades the inclined flanks of the teeth of the inter-engaging detents slide over one another, whilst on any unwanted reverse movement the then adjacent perpendicular flanks of the teeth come into engagement and prevent or at least make difficult any reverse movement.
A base of the container may have a recess for receiving a rail designed to guide the slide member. The arrangement is such that an upper face of the rail lies in the same plane as the base so that the knife blades lie against a substantially continuous surface without rattling.
If, according to a preferred embodiment, the rail has two lower flanges on the side adjacent to the base by which the rail is wider than the slide in the region of the engagement, there is always play between the slide member and side walls which bound the recess in base. Accordingly the slide member does not rub against the base.
The slide member may have interengaging portions engaging over the upper flange of the rail to provide a mechanical inter-engagement. This provides stability of the slide member against tilting and rotation, together with good sliding and guiding characteristics.
The slide member may have a guiding membe and/or a wall member bounding the internal cavity. The guiding member is provided for moving the slide member. The guiding member is constructed so that the slide is particularly easy to move in the desired direction, which can for example be achieved by arranging that the guiding member is upwardly inclined in the direction of sliding or it has a surface which is able to be grasped preferentially in the direction of sliding, which can also be achieved by providing openings in the guiding member.
Openings provided in the guiding member are particularly advantageous if for example the rail which is made overall of a yellow colour is visible through a dark-coloured guiding member and the openings have shapes (e.g. an xe2x80x9carrowxe2x80x9d motif), which are of assistance in explaining the manner of using the article and accordingly serve as an operating instruction. In this way there is no need to print or stick on labels for such indications.
In one embodiment a gap is provided in the wall member provided on the slide member, making it possible to engage the currently leading blade in the stack with the finger and to withdraw it from the stack using the frictional force arising between blade and finger.
The rail is particularly adaptable in use if for example preferential fracture points are provided, formed by thinning of the material, by which the rail can easily be shortened by breaking off to different lengths for different packs. In this way the number of variants which need to be manufactured is reduced and the rail is cheap to manufacture by virtue of the large numbers produced.
The container for the blades can be made either conventionally of cardboard or can be formed of an upper and lower shell of deep-drawn polystyrene or other plastics.
A further embodiment of the invention envisages that an insert of deep-drawn polystyrene or another plastics is provided in the lower shell of the container and matched to the rail and blades to be received on it.
The invention also relates to a method of removing knife blades from a stack in a container, wherein at least one blade is removed from the stack, and slide means arranged in the container are displaced towards the stack of blades.